In an enterprise environment, an active call between a first caller's user agent (UA1) and a callee's user agent (UA2) has been put on hold by UA2. The call has been on hold for quite a long time, which may be subjective based on factors such as the caller's patience. If the user of UA1 wishes to communicate with UA2, they must utilize another communication channel (e.g., email, text message, attempt to drop and re-establish the call, etc.). The UA1 cannot do anything to get back to UA2 to indicate that the call has been put on hold for quite a long duration and expects some action.
In a call center environment, an active call between a caller (customer) and a call center agent has been put on hold by an agent, such as to allow the agent to investigate an issue. The caller also investigates the issue and discovers a fact that may assist the agent in resolving the issue. The caller would like to provide this newly discovered fact to the agent; however, the agent has placed the call on hold. The caller is forced to wait until the agent resumes the call or the customer hangs up, perhaps to call back to start anew with a new agent.